1. Combine flour, sugar and salt in an electric mixer. Add butter to the dry ingredients. Using the paddle attachment, carefully knead dough until butter is the size of marbles. Mix yolks and milk; add to flour mixture and mix until dough barely comes together. It should look shaggy.

2. Transfer dough to work surface and with your hands, press dough until it just comes together. There should be visible streaks of butter throughout. Form into a disk and chill for 4 hours.

6. Lay half the pastry rectangles on a parchment-lined baking sheet. Place a dollop of filling in the center of each, leaving enough space to crimp the sides. Brush the edges with egg wash; top with another pastry rectangle. Crimp edges with a fork and cut a small incision in the top to vent the steam. Bake for about 12 minutes or until golden brown.